1. Field of the Invention
This invention relates to couplings for misaligned reciprocating shafts found in connecting the piston rod of a hydraulic piston and cylinder assembly to a work piece moved thereby.
2. Description of the Prior Art
Prior art devices have used a number of different structures. See for example U.S. Pat. Nos. 3,414,302, 3,406,992 and 4,203,683.
In U.S. Pat. No. 3,414,302, a coupling has a housing with a large opening in each end, a stud with a threaded socket in a curved end extends through one chamber and through an exposed opening in a retainer ring, a flanged fitting extends through the other exposed opening.
In U.S. Pat. No. 3,406,992, a housing with chamber in its ends receives a fitting closing one circular chamber and a stud with an annular flange is positioned through the other opening which is exposed.
U.S. Pat. No. 4,203,683 discloses substantially the same open structure about a ball end on a stud. The structures of these patents permit ready contamination of the areas in the couplings through the exposed openings and the couplings have a very short life due to rapid wear.
The present invention seals the openings in the coupling and thus prevents wear due to foreign material and additionally coats the wear surfaces with a slippery material by impregnation.
Applicant's invention allows for coupling misaligned shafts by positioning a concave annular flange ended stud on one shaft between a pair of guide elements. A movable seal encircles the stud maintaining the interior integrity of the coupling. The guide elements are in a housing to which the other shaft is attached. No contaminates can enter the housing.